scholarly journals Monosomy 18p is a risk factor for facioscapulohumeral dystrophy

2018 ◽  
Vol 55 (7) ◽  
pp. 469-478 ◽  
Author(s):  
Judit Balog ◽  
Remko Goossens ◽  
Richard J L F Lemmers ◽  
Kirsten R Straasheijm ◽  
Patrick J van der Vliet ◽  
...  
Keyword(s):  
Neurological Examination ◽  
Clinical Symptoms ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Cellular Systems ◽  
Deletion Syndrome ◽  
Facial Dysmorphism ◽  
D4z4 Repeat ◽  
Molecular Features ◽  
Digenic Inheritance ◽  
Primary Fibroblasts

Background18p deletion syndrome is a rare disorder caused by partial or full monosomy of the short arm of chromosome 18. Clinical symptoms caused by 18p hemizygosity include cognitive impairment, mild facial dysmorphism, strabismus and ptosis. Among other genes, structural maintenance of chromosomes flexible hinge domain containing 1 (SMCHD1) is hemizygous in most patients with 18p deletions. Digenic inheritance of a SMCHD1 mutation and a moderately sized D4Z4 repeat on a facioscapulohumeral muscular dystrophy (FSHD) permissive genetic background of chromosome 4 can cause FSHD type 2 (FSHD2).ObjectivesSince 12% of Caucasian individuals harbour moderately sized D4Z4 repeats on an FSHD permissive background, we tested if people with 18p deletions are at risk of developing FSHD.MethodsTo test our hypothesis we studied different cellular systems originating from individuals with 18p deletions not presenting FSHD2 phenotype for transcriptional and epigenetic characteristics of FSHD at D4Z4. Furthermore, individuals with an idiopathic muscle phenotype and an 18p deletion were subjected to neurological examination.ResultsPrimary fibroblasts hemizygous for SMCHD1 have a D4Z4 chromatin structure comparable with FSHD2 concomitant with DUX4 expression after transdifferentiation into myocytes. Neurological examination of 18p deletion individuals from two independent families with a moderately sized D4Z4 repeat identified muscle features compatible with FSHD.Conclusions18p deletions leading to haploinsufficiency of SMCHD1, together with a moderately sized FSHD permissive D4Z4 allele, can associate with symptoms and molecular features of FSHD. We propose that patients with 18p deletion should be characterised for their D4Z4 repeat size and haplotype and monitored for clinical features of FSHD.

scholarly journals Does DNA Methylation Matter in FSHD?

Genes ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 258 ◽  
Author(s):  
Valentina Salsi ◽  
Frédérique Magdinier ◽  
Rossella Tupler
Keyword(s):  
Dna Methylation ◽  
Developmental Disorder ◽  
Methylation Status ◽  
Disease Status ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Icf Syndrome ◽  
D4z4 Repeat ◽  
Molecular Features ◽  
Reliable Marker ◽  
Induced Pluripotent

Facioscapulohumeral muscular dystrophy (FSHD) has been associated with the genetic and epigenetic molecular features of the CpG-rich D4Z4 repeat tandem array at 4q35. Reduced DNA methylation of D4Z4 repeats is considered part of the FSHD mechanism and has been proposed as a reliable marker in the FSHD diagnostic procedure. We considered the assessment of D4Z4 DNA methylation status conducted on distinct cohorts using different methodologies. On the basis of the reported results we conclude that the percentage of DNA methylation detected at D4Z4 does not correlate with the disease status. Overall, data suggest that in the case of FSHD1, D4Z4 hypomethylation is a consequence of the chromatin structure present in the contracted allele, rather than a proxy of its function. Besides, CpG methylation at D4Z4 DNA is reduced in patients presenting diseases unrelated to muscle progressive wasting, like Bosma Arhinia and Microphthalmia syndrome, a developmental disorder, as well as ICF syndrome. Consistent with these observations, the analysis of epigenetic reprogramming at the D4Z4 locus in human embryonic and induced pluripotent stem cells indicate that other mechanisms, independent from the repeat number, are involved in the control of the epigenetic structure at D4Z4.

Primary Leptomeningeal Gliomatosis in Children and Adults: A Morphological and Molecular Comparative Study With Literature Review

Neurosurgery ◽  
2015 ◽  
Vol 78 (3) ◽  
pp. 343-352 ◽  
Author(s):  
Arnault Tauziede-Espariat ◽  
Andre Maues de Paula ◽  
Melanie Pages ◽  
Annie Laquerriere ◽  
Emilie Caietta ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Overall Survival ◽  
Cerebrospinal Fluid ◽  
Nervous System ◽  
Clinical Symptoms ◽  
Malignant Gliomas ◽  
Leptomeningeal Gliomatosis ◽  
Molecular Features ◽  
The Central Nervous System ◽  
The Mean

Abstract BACKGROUND: Primary leptomeningeal gliomatosis (PLG) is a poorly recognized tumor of the central nervous system. OBJECTIVE: To describe the histopathological, immunohistochemical, and molecular features of PLG. METHODS: Results of our multicentric retrospective study of 6 PLG cases (3 pediatric and 3 adult) were compared with literature data. RESULTS: The mean age was 54.7 years for adults and 8.7 years for children, with 3 males and 3 females. Clinical symptoms were nonspecific. Cerebrospinal fluid analyses showed a high protein level often associated with pleocytosis but without neoplastic cells. On neuroimaging, diffuse leptomeningeal enhancement and hydrocephalus were observed, except in 1 case. PLG was mostly misinterpreted as infectious or tumoral meningitis. The first biopsy was negative in 50% of cases. Histopathologically, PLG cases corresponded to 1 oligodendroglioma without 1p19q codeletion and 5 astrocytomas without expression of p53. No immunostaining for IDH1R132H and no mutations of IDH1/2 and H3F3A genes were found. Overall survival was highly variable (2-82 months) but seems to be increased in children treated with chemotherapy. CONCLUSION: This study shows the difficulties of PLG diagnosis. The challenge is to achieve an early biopsy to establish a diagnosis and to begin a treatment, but the prognosis remains poor. PLG seems to have a different molecular and immunohistochemical pattern compared with intraparenchymal malignant gliomas.

scholarly journals Type 1 FSHD with 6–10 Repeated Units: Factors Underlying Severity in Index Cases and Disease Penetrance in Their Relatives Attention

2020 ◽  
Vol 21 (6) ◽  
pp. 2221
Author(s):  
Emmanuelle Salort-Campana ◽  
Farzad Fatehi ◽  
Sadia Beloribi-Djefaflia ◽  
Stéphane Roche ◽  
Karine Nguyen ◽  
...  
Keyword(s):  
Disease Severity ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Clinical Severity ◽  
Cross Sectional ◽  
Repeat Array ◽  
D4z4 Repeat ◽  
Severity Scores ◽  
Group 2 ◽  
Group 1

Molecular defects in type 1 facioscapulohumeral muscular dystrophy (FSHD) are caused by a heterozygous contraction of the D4Z4 repeat array from 1 to 10 repeat units (RUs) on 4q35. This study compared (1) the phenotype and severity of FSHD1 between patients carrying 6–8 vs. 9–10 RUs, (2) the amount of methylation in different D4Z4 regions between patients with FSHD1 with different clinical severity scores (CSS). This cross-sectional multicenter study was conducted to measure functional scales and for genetic analysis. Patients were classified into two categories according to RUs: Group 1, 6–8; Group 2, 9–10. Methylation analysis was performed in 27 patients. A total of 99 carriers of a contracted D4Z4 array were examined. No significant correlations between RUs and CSS (r = 0.04, p = 0.73) and any of the clinical outcome scales were observed between the two groups. Hypomethylation was significantly more pronounced in patients with high CSS (>3.5) than those with low CSS (<1.5) (in DR1 and 5P), indicating that the extent of hypomethylation might modulate disease severity. In Group 1, the disease severity is not strongly correlated with the allele size and is mostly correlated with the methylation of D4Z4 regions.

scholarly journals Homozygous nonsense variant in LRIF1 associated with facioscapulohumeral muscular dystrophy

Neurology ◽  
2020 ◽  
Vol 94 (23) ◽  
pp. e2441-e2447 ◽  
Author(s):  
Kohei Hamanaka ◽  
Darina Šikrová ◽  
Satomi Mitsuhashi ◽  
Hiroki Masuda ◽  
Yukari Sekiguchi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Muscular Dystrophy ◽  
Target Gene ◽  
Disease Gene ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Target Gene Expression ◽  
D4z4 Repeat ◽  
Biopsy Examination ◽  
Chromatin Relaxation

ObjectiveFacioscapulohumeral muscular dystrophy (FSHD) is a heterogenetic disorder predominantly characterized by progressive facial and scapular muscle weakness. Patients with FSHD either have a contraction of the D4Z4 repeat on chromosome 4q35 or mutations in D4Z4 chromatin modifiers SMCHD1 and DNMT3B, both causing D4Z4 chromatin relaxation and inappropriate expression of the D4Z4-encoded DUX4 gene in skeletal muscle. In this study, we tested the hypothesis whether LRIF1, a known SMCHD1 protein interactor, is a disease gene for idiopathic FSHD2.MethodsClinical examination of a patient with idiopathic FSHD2 was combined with pathologic muscle biopsy examination and with genetic, epigenetic, and molecular studies.ResultsA homozygous LRIF1 mutation was identified in a patient with a clinical phenotype consistent with FSHD. This mutation resulted in the absence of the long isoform of LRIF1 protein, D4Z4 chromatin relaxation, and DUX4 and DUX4 target gene expression in myonuclei, all molecular and epigenetic hallmarks of FSHD. In concordance, LRIF1 was shown to bind to the D4Z4 repeat, and knockdown of the LRIF1 long isoform in muscle cells results in DUX4 and DUX4 target gene expression.ConclusionLRIF1 is a bona fide disease gene for FSHD2. This study further reinforces the unifying genetic mechanism, which postulates that FSHD is caused by D4Z4 chromatin relaxation, resulting in inappropriate DUX4 expression in skeletal muscle.

scholarly journals Early-Onset Infantile Facioscapulohumeral Muscular Dystrophy: A Timely Review

2020 ◽  
Vol 21 (20) ◽  
pp. 7783
Author(s):  
Tai-Heng Chen ◽  
Yan-Zhang Wu ◽  
Yung-Hao Tseng
Keyword(s):  
Muscular Dystrophy ◽  
Early Onset ◽  
Case Reports ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Clinical Severity ◽  
Genetic Diagnostics ◽  
Rapid Decline ◽  
Novel Treatments ◽  
D4z4 Repeat ◽  
History Of

Facioscapulohumeral muscular dystrophy (FSHD)—the worldwide third most common inherited muscular dystrophy caused by the heterozygous contraction of a 3.3 kb tandem repeat (D4Z4) on a chromosome with a 4q35 haplotype—is a progressive genetic myopathy with variable onset of symptoms, distribution of muscle weakness, and clinical severity. While much is known about the clinical course of adult FSHD, data on the early-onset infantile phenotype, especially on the progression of the disease, are relatively scarce. Contrary to the classical form, patients with infantile FSHD more often have a rapid decline in muscle wasting and systemic features with multiple extramuscular involvements. A rough correlation between the phenotypic severity of FSHD and the D4Z4 repeat size has been reported, and the majority of patients with infantile FSHD obtain a very short D4Z4 repeat length (one to three copies, EcoRI size 10–14 kb), in contrast to the classical, slowly progressive, form of FSHD (15–38 kb). With the increasing identifications of case reports and the advance in genetic diagnostics, recent studies have suggested that the infantile variant of FSHD is not a genetically separate entity but a part of the FSHD spectrum. Nevertheless, many questions about the clinical phenotype and natural history of infantile FSHD remain unanswered, limiting evidence-based clinical management. In this review, we summarize the updated research to gain insight into the clinical spectrum of infantile FSHD and raise views to improve recognition and understanding of its underlying pathomechanism, and further, to advance novel treatments and standard care methods.

scholarly journals Clinical, Immunological, and Molecular Features of Severe Combined Immune Deficiency: A Multi-Institutional Experience From India

2021 ◽  
Vol 11 ◽  
Author(s):  
Pandiarajan Vignesh ◽  
Amit Rawat ◽  
Rajni Kumrah ◽  
Ankita Singh ◽  
Anjani Gummadi ◽  
...  
Keyword(s):  
Immune Deficiency ◽  
Opportunistic Infections ◽  
Clinical Symptoms ◽  
Age Of Onset ◽  
Easy Access ◽  
Severe Combined Immune Deficiency ◽  
Hematopoietic Stem ◽  
Female Ratio ◽  
Molecular Features ◽  
Combined Immune Deficiency

BackgroundSevere Combined Immune Deficiency (SCID) is an inherited defect in lymphocyte development and function that results in life-threatening opportunistic infections in early infancy. Data on SCID from developing countries are scarce.ObjectiveTo describe clinical and laboratory features of SCID diagnosed at immunology centers across India.MethodsA detailed case proforma in an Excel format was prepared by one of the authors (PV) and was sent to centers in India that care for patients with primary immunodeficiency diseases. We collated clinical, laboratory, and molecular details of patients with clinical profile suggestive of SCID and their outcomes. Twelve (12) centers provided necessary details which were then compiled and analyzed. Diagnosis of SCID/combined immune deficiency (CID) was based on 2018 European Society for Immunodeficiencies working definition for SCID.ResultsWe obtained data on 277 children; 254 were categorized as SCID and 23 as CID. Male-female ratio was 196:81. Median (inter-quartile range) age of onset of clinical symptoms and diagnosis was 2.5 months (1, 5) and 5 months (3.5, 8), respectively. Molecular diagnosis was obtained in 162 patients - IL2RG (36), RAG1 (26), ADA (19), RAG2 (17), JAK3 (15), DCLRE1C (13), IL7RA (9), PNP (3), RFXAP (3), CIITA (2), RFXANK (2), NHEJ1 (2), CD3E (2), CD3D (2), RFX5 (2), ZAP70 (2), STK4 (1), CORO1A (1), STIM1 (1), PRKDC (1), AK2 (1), DOCK2 (1), and SP100 (1). Only 23 children (8.3%) received hematopoietic stem cell transplantation (HSCT). Of these, 11 are doing well post-HSCT. Mortality was recorded in 210 children (75.8%).ConclusionWe document an exponential rise in number of cases diagnosed to have SCID over the last 10 years, probably as a result of increasing awareness and improvement in diagnostic facilities at various centers in India. We suspect that these numbers are just the tip of the iceberg. Majority of patients with SCID in India are probably not being recognized and diagnosed at present. Newborn screening for SCID is the need of the hour. Easy access to pediatric HSCT services would ensure that these patients are offered HSCT at an early age.

scholarly journals Chromosome 10q-linked FSHD identifies DUX4 as principal disease gene

2021 ◽  
pp. jmedgenet-2020-107041
Author(s):  
Richard J L F Lemmers ◽  
Patrick J van der Vliet ◽  
Ana Blatnik ◽  
Judit Balog ◽  
Janez Zidar ◽  
...  
Keyword(s):  
Gene Expression ◽  
Candidate Genes ◽  
De Novo ◽  
Disease Model ◽  
Chromosome 4 ◽  
Chromosome 10 ◽  
D4z4 Repeat ◽  
Molecular Features ◽  
Dominant Disease ◽  
Transcriptional Deregulation

BackgroundFacioscapulohumeral dystrophy (FSHD) is an inherited muscular dystrophy clinically characterised by muscle weakness starting with the facial and upper extremity muscles. A disease model has been developed that postulates that failure in somatic repression of the transcription factor DUX4 embedded in the D4Z4 repeat on chromosome 4q causes FSHD. However, due to the position of the D4Z4 repeat close to the telomere and the complex genetic and epigenetic aetiology of FSHD, there is ongoing debate about the transcriptional deregulation of closely linked genes and their involvement in FSHD.MethodDetailed genetic characterisation and gene expression analysis of patients with clinically confirmed FSHD and control individuals.ResultsIdentification of two FSHD families in which the disease is caused by repeat contraction and DUX4 expression from chromosome 10 due to a de novo D4Z4 repeat exchange between chromosomes 4 and 10. We show that the genetic lesion causal to FSHD in these families is physically separated from other candidate genes on chromosome 4. We demonstrate that muscle cell cultures from affected family members exhibit the characteristic molecular features of FSHD, including DUX4 and DUX4 target gene expression, without showing evidence for transcriptional deregulation of other chromosome 4-specific candidate genes.ConclusionThis study shows that in rare situations, FSHD can occur on chromosome 10 due to an interchromosomal rearrangement with the FSHD locus on chromosome 4q. These findings provide further evidence that DUX4 derepression is the dominant disease pathway for FSHD. Hence, therapeutic strategies should focus on DUX4 as the primary target.

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